The long-term goal of this research is to provide information of potential use in the clinical management or prevention of certain respiratory diseases, such as respiratory distress syndrome, through analysis of the regulation of surfactant biosynthesis in cultured alveolar type II pneumocytes. At the outset, studies will be conducted using cells isolated from the adenoma tumors of mouse lung. On electron microscopy, these cells contain intracytoplasmic lamellar inclusion bodies similar in appearance to those observed in the adenoma in situ, and in the normal type II cell precursor of the adenoma. In addition, attempts will be made to isolate type II alveolar cells from normal mouse, human and monkey lung tissues. The kinetics of lecithin production and release from the cells will be examined and compared to that of other lung cell types of the same species. Using radio labeled precursors, the biochemical pathways for surfactant production will be investigated. Further, the effects of various hormones, levels of O2 tension and media formulation on surfactant synthesis and release from the cells will be examined. Bibliographic references: Stoner, G.D. "Hormone-mediated differentiation of mouse lung adenoma cells". In Vitro 9:381, 1974; Stoner, G.D. and Shimkin, M.B. "Characteristics of cells cultured from the adenoma tumor of mouse lung". Proc. Am. Assn. Cancer Res. 16:93/372, 1975.